Synthetic fiber



June 6, 193 E. w. RUGELEY ET AL 2,161,766

SYNTHETIC FIBER Filed Sept. 15, 1937 l SOLVENT VINYL RESIN SPINNING HOTWATER DELUSTERING LUSTROUS FILAMENTS ::l I DOUBLING TWISTING WATERLUBRICATION I COLD STRETCHING HOT ROLL STRETGHING ONE OR MORE STAGESWATE LURICATION SINGLE STAGE HOT WATEI? AGEING WATER LUBRICATION FINALPACKAGING m 3.40 150 g 3.20 120 Z 300 no 5 Lu Q I- m 2.8 100 g E 260 warmonomer: 90 g 240 so A 2 TENACITY H g 2.20 7

. Q |..J I 2.00 so 0 ,2 L60 50 E Q 1.60 40 Z M 7.40 30 1.20 20 0 4O 6O80 I00 I20 I 760 Z00 INVENTORS EDWARD W. RUGELEY THEOPHILUS A. FEILD,JR.

JOHN FCONLON BY @102 6. J

ATTORNE Patented June 6, 1939 PATENT OFFICE- SYNTHETIC FIBER Edward w.Bugeley,

'l'heophilus John F. Conlon, Charleston. W. Va.,

' A. 1"eild, Jr., and ors to Carbide and Carbon Chemicals Corporation, acorporation of New York Application September 15, 1931, Serial No.104,002

The quest for a truly synthetic textile fiber has had few rivals in itsintensity, and, through the past, in its conspicuous lack of success. Ithas been-proposed to make textile fibers and filas ments from manysynthetically produced materials, but until now none of these has everyielded acommercially usable product. The only commercially usefultextile fibers at present, as in the beginning, are products of nature,supplemented in more recently by those made from chemically modifiednatural products, such as the esters and ethers of cellulose, andcellulose itself regenerated from its derivatives.

This invention makes possible a synthetic fiber ll of many unique anddistinctive properties, in-

cluding high true elasticity, flexibility. high strength and remarkableresistance, and it provides an easily producible product not originatingin nature which equals and surpasses in many respects natural fibers andfibers made from modified products of nature. The synthetic fibers ofthis invention are formed of certain types of vinyl resins, and theinvention includes methods of forming, treating and using the newfibers, all as more fully hereinafter described.

Vinyl resins have been proposed for use in forming textile fibers bynearly all who have had experience with them, and this was entirely tobe expected, since these resins are products which are truly synthetic,as well as readily formable, inherently colorless, odorless, tasteless,and not readily inflammable. Nevertheless, in the twenty years and moresince vinyl resins first were suggested for this purpose, useful orpractical fibers have never been produced from any vinyl resin of thesetypes...

The new fibers of this invention are formed from vinyl resins such asmay result from the conjoint polymerization of vinyl halides with vinyl40 esters of aliphatic acids, and which have an average macromolecularweight of at least about 15,000. (Molecular weights referred to hereinare those calculated by means of Staudinger's formula from viscositydeterminations of solutions of the resins.)

Briefly, the fibers are formed by spinning a solution or dispersion ofthe vinyl resin into filaments. These filaments are formed into fibersof the desired size by twisting and doubling operations as desired, andthereafter the fibers are stretched to yield products suitable for usein the customary textile operations. The stretching of the fibers iscarried out while they are in their normal state, by which is meant thatthey are not softened by heat or by the action of a solvent.

This stretching operation is a vital feature in the production of usefultextile fibers from the vinyl resins, and it serves the dual purpose ofgreatly increasing the tensile strength, and of conferring on the fibersthe unusual and highly 5 desirable property of true elasticity. By meansof the stretching operation, the two highly imlportant properties oftenacity and elongation may be varied and controlled almost at will.

The fibers in finished form are soft and fiexible, and are characterizedby their ability to be woven and knitted and formed into a large numberof exceptionally useful materials. The new fibers possess a very highstrength by comparison with other textile fibers, and they are unusualin that their strength is virtually the same whether they are wet ordry, and, surprisingly enough, the wet strengthof the new fibers is, ifanything, slightly greater than the dry strength. The unique resistanceto impairment by water, together with the true elasticity, resistance tochemical, bacterial and fungal attack, thermoplasticity, lack ofinfiammability and great flexibility of the fibers, makes possible manyuses for these materials which are radically different from those towhich ordinary textile fibers are applicable.

The general sequence of operations in the formation of the new textilefibers according to this invention is shown by the fiow sheet appearingas Fig. 1 in the accompanying drawing.

As has been indicated, the vinyl resins from which the new fibers areprepared must have special characteristics. The class of resins use-,ful in this invention are those such as are described in Patent1,935,577 to E. W. Reid, and these resins may be made by the processesdescribed by that patent or by other means, such as the processdescribed in Patent 2,064,565 to E. W. Reid. of these conjoint polymersof vinyl halides with vinyl esters of aliphatic acids, the preferredresins are those which contain from to 95% by weight of the halide inthe polymer. Within this range, those resins formed from vinyl chlorideand vinyl acetate which contain in the polymer about to by weight of thechloride are especially desirable.

The resin must have an average macromolecular weight of at least 15,000,and the upper value is limited only by the solubility of the resins insuitable liquids to yield spinnable solutions or dispersions. Vinylresins, as prepared, ordinarily consist of a mixture of polymericaggregates of different molecular sizes. .Those to be used in thisinvention should be freed from polymers 55 havingexcessively lowmolecular weightsin orweight of water. It has been found that, when theacetone used contains water in excess of this amount, the quality of theresin dispersion is materially impaired, and solutions made from suchsolvents can be filtered and spun only with great difiiculty. Theconcentration of the vinyl resin in the spinning solution is dependentupon and varies inversely with themacromolecular weight of the resin,but theresin content ordinarily employed using acetone as the solvent is25% or less by weight. In forming the solution, the resin is bestemployed in the form of a dry powder, and the dispersion, or thespinning dope, may be made bycombining the resin with the requisitequantity of dry acetone in a mixing device, such as one of thedough-type mixers or kneaders, provided with means of temperaturecontrol, and equipped to eflect reflux of the solvent. The temperatureof mixing and subsequent handling is conveniently maintained at about 50C. The time required for mixing to obtain useful dispersions must beadjusted according to the ease of dispersion or the resin in thesolvent, and this ordinarily consumes about 12 hours. The resultingdope" is a clear, heavily gelatinous, non-flowing, plastic mass at roomtemperature, while at a temperature of 50 C. it assumes a very viscous,slowly fiowable state. This viscosity has been determined by experimentto be desirable in the subsequent manipulation of the solution and itsformation into filaments.

The dispersion, or "dope, may be filtered in high-pressure typeplate-and-frame filters, the material being moved by means ofhigh-pressure gear-type pumps. Throughout the handling. of thesedispersions, it is highly desirable to provide all storage tanks andconduits with temperature control means, such as jackets supplied withheated water or steam, so that an elevated temperature may be maintainedto reduce the pressure necessary to handle the viscous mass.

Filtration may be carried out in one or more stages, and the filteringmedium may be any suitable material capable'of removing the last tracesof undispersed or insoluble material from the dope. Filteringv pressuresof from about 200 to 500 pounds per square inch, in general, aresuitable for this operation. The filtered dope should be thoroughlyde-aerated, and this may be efiected by permitting the dispersion tostand for about 24'hours at the operating temperature of 50 C., and thismay be assisted, if desired, by creating a partial vacuum over thedispersion.

The spinning, or filament extrusion, operation may be carried out inequipment customarily employed for so-called dry-spinning of other typesof filaments, A bobbin-type thread takeup may be employed, orthefilaments may be given a twist at the point of spinning by employing acap-type mechanism. In the spinning device, or drying cell, thefilaments are dried by heated air or other gas, and the length of thedrying cell is determined by the rate of drying so eflected. In general,the length of drying cell required for the formation of these vinylresin filaments is somewhat greater than is. true of other plasticmaterials,such as the cellulose esters, because of the tendencies of thematerial to retain the solvent. It is desirable to direct astream ofwater heated to a temperature above 50 C. on the thread at the take-upbobbin. This serves to remove or dilute any solvent retained by thefilaments and thereby to prevent sub sequent fusion of the fibers orloss of their identity as individual filaments. At the same time,

this treatment produces delustering oi the fibers which persists inlarge part throughout their formation into finished yarn. This method ofdelusterlng the fibers has no efiect on their tensile properties,elasticity, or other qualities, and because of its simplicity andeconomy it has obvious advantages over delustering methods which involvethe addition 0! foreign substances to the filaments themselves.

The filaments or thread delivered from the take-up bobbin may betwisted, or doubled and twisted, to form a yarn. It is necessary in mostcases to permit the filaments to age for at least 12 hours before thetwisting or doubling operations are performed. Ageing of the can beadvantageously replaced by a bri ttreatment with heated water. Forexample, ii! the filaments on the bobbins are immersed in water at 65 C.for a period oi 2 to 5 hours, no ageing is required. Throughout allhandling and transferring of the threads or filaments in such operationsas doubling and'twisting, the fibers must be lubricated, and for thispurpose water is quite satisfactory, since it serves the dual purpose oilubrication and reduction or static electrical charges which otherwisewould develop on the yarn. The remarkable resistance of these new fibersto impairment in any way by water makes it possible to carry out thetwisting, and similar operations, from bobbins of the yarn immersed inwater.

The fibers, after twisting or twisting and doubling, are to bestretched, and it is therefore necessary initially to impart greatertwist than is intended for the finished yarn, inasmuch as the stretchingoperation obviously will reduce the twist per unit length oi. the yarn.Allowance for reduction in twist as a result of stretching the yarn is adirect linear function or the degree of stretch to be given the fibers,and can be readily computed.

The next step in the yarn processing is that of stretching, and thisstep is one of paramount importance in the production of the new fibers,The amount of stretch-imparted to the yarn may vary considerably up toabout 200%, and in normal procedure a stretch of from about 75% to about180% is applied. The extent of stretch used is determinedby the polymersize (average macromolecular weight) of the resin, and by thecharacteristics desired in the finished yarn. It is important to conductthis operation while the yarn is adequately surface-wetted, and this maybe done by immersing, or partly immersing, the spools from which theyarn is to be stretched in water which may contain a wetting agent orsurface tension depressant, such as a sodium salt of a higher alkylsulfate, or another of the materials commonly used for this purpose intextile operations. The actual stretching of the yarn n be eccqmp s edby any means which will lamentseifectthenecusaryextemiomanditcanbeconvenientlycarriedoutbytransferringtheyarnfromtbespooionwbichitiscontainedtoa second spool positively driven at ahigher speed thanthatatwhichthefirstspoolisallowedto rotate.Inanothertypicalarrangement, the yarn,astwisted,canbestretchedbyimmersingthe bobbinincoldwaterandbrlngltheyarnfrom this bobbin once around a roll positively driven subsequentoperations given additional stretchingto the extent of 10% or 20% ineach stage. If water heated to about to 00 C. is applied to the yarn atthe first driven roll, and a stretch in excess of is applied, the yarnis delustered simultaneously with the stretching operation. In the caseof stretching in the cold in two or more stages, the yarn is alsodelustered, but to a lesser extent than is true when the high degree ofstretch is applied in a single stage. The application of heated water tothe yarn just prior to stretching apparently does not cause the yarn tobe stretched while appreciably softened by heat, since it is likely thatmost of the heat is dissipated prior to the actual stretching of theyarn. This has been demonstrated, in some cases, by the fact that heatedwater applied to the yarn at points intermediate to the two driven rollshad the apparent effect of restoring some luster to the yarn, andresulting in the production of yarn of lower quality than was otherwiseproduced by the preferred stretching operation described above.

Throughout all such operations, suitable traverse movements should beemployed to provide correct cake-build of the yarn on the several spoolsand bobbins.

For a period after the yarn has been stretched, it shows a markedtendency to contract. This characteristic may be rudily controlled andmodified by a setting" treatment. The setting of the stretch in the yarnmay be accomplished in several ways; for example, by prolonged ageing ofthe extended yarn under tension on the stretcher spool, or by subjectingthe tensioned stretched yarn to elevated temperatures, which greatlyaccelerate the rate of setting. The latter treatment may be convenientlycarried out by immersing the yarn contained on the stretcher spools inwater heated to the desired temperature, or by applying water so heatedto the revolving stretcher spool. This latter procedure enablesstretching and setting of the yarn to be conducted simultaneously. Thetemperature of the setting operation depends upon the propertiesultimately desired in the yarn, and these effects are more fullydescribed below. In general, the stretched yarn may be set at anytemperature below about 75 C. If the yarn is stretched in severalstages, the stretch may be set in the yarn between each stage ofstretching. Immersion of the stretched yarn in water at about 65 C. for2 to 3 hours will accomplish this.

Ithasbeen observedthattheyarnprocessed as described above did not alwayspossess a uniform softness or hand. This was particularly noticeablebetween portions of the yarn wound nexttothebobbinorspoolascompared withthatneartheoutsideoftheyarncake,thatonthe outside being softer than thatfirst wound on the bobbin. This irregularity can be eliminated, and yarnof lmiformly desirable hand and softness can be produced by subjectingthe stretched yarn to abrupt flexing at high speeds while immersed inwater. Such flexing can be easily carried out by simply transferring theyarn from one bobbin to another by way of an intermediate roller or setof rollers operating under water and arranged to cause the yarn passingover it to change directionthrough a short radius once or several times.For example, three rollers of small diameter, say 0.125 inch, may bestaggered to cause the yarn to change direction abruptly as it passesover each roller. If an idler roll of large diameter is used with suchan arrangement, the yarn may be sharply flexed in this manner threetimes, or some multiple of three times, in each pass through thearrangement, depending on the num, ber of turns of yarn over the idlerroll.

As has been stated, the characteristics of the finished yarnarelargelyoontrolled by,the stretching operation. In any textile fiberthe properties of filament size, softness, luster, strength, supplenessor flexibility, and extensibility or elongation are of extremeimportance. It is desirable to have the proper balance between theseproperties, particularly those of strength, or tenacity, and elongation.The yarn produced in accordance with this invention before stretchingmay have, for example, a tenacity of 0.83 gram per denier. and anelongation of 120% or more. When this same yarn had been stretched asdescribed herein to the extent of 90%, the re-' sultant productpossessed a tenacity of 2.00 gramsper denier and an elongation of 35%.If, for example, the same, or a similar, yarn were stretched to theextent of (based on the original yarn), the product resulting may show atenacity of 3.40 grams per denier and an eion-- gation of 11%. Theforegoing examples will clearly show that, by controlling the degree ofstretch imparted to the yarn, the tensile properties of the product canbe varied almost at will. As the amount of stretch is increased, theelongation is correspondingly reduced until an impracticaliy low valuefor the latter is reached. This correlation of the tenacity andelongation with the degree of stretch is illustrated by the accompanyingdrawing, in which Fig. 2 graphically represents this relation ofproperties as it exists in one particular sample of yarn.

.The finished yarn may be packaged according to any of the conventionalforms in which yarn is supplied by employing any standard equipment fortransferring the yarn from the spools or bobbins containing thestretched and flexed yarn to the final packages. For example, spooling,capping, skeining, and coning may be readily carried out, and in suchoperations as coning, where lubricants are required, these may beconveniently applied to the yarn by means of a conditioning roll.

All of the foregoing is directed primarily to the production of textilefibers in which continuous filaments are employed. It is also possibleto apply these procedures to the formation of staple fibers, orartificial wool-like masses. The filaments of this invention 'may beused in this manner either in the unstretched or stretched condition,and the shorter filaments, or staple fibers, are particularly desirablefor use in conjunction with other types of natural or artificial textilefibers.

The staple fiber produced from unstretched filaments of the type shownherein is particularly useful as a binding agent or stlfiener forExample 1 A vinyl resin resulting from the conjoint polymerization ofvinyl chloride with vinyl acetate in such proportions as to produce aresin confirming 87% of the chloride in the polymer was eatedby'fractional extraction according to the method of Patent 1,990,685 tofree the polymeric aggregate from the lower average macromolecularweight polymers, and to yield a resin having an average macromolecularweight of about 17,- 000. This resin conformed to the followingspecifications, which are, in general, applicable for determining thesuitability of vinyl resins for use in the practice of the invention:

1. Complete dispersibility in warm dry acetone.

2. Average macromolecular weight in excess of 3. Impact strength (Izodnotched bar method, A. S. T. M!) not less than 0.32 foot pounds/ piece.

A. S. T. M. specification D-256-32'I, modified in that the test piece isconditioned for 4 hours at 25 C.

4. Tensile strength (Olsen method, A. S. 'I. M.) not less than 9500pounds/square inch.

5. Plasticity in oil at 140 C. (Scott Plastometer) not greater than 10%.

' 6. Heat distortion point not less than 66 C.

7. Water absorption not greater than 0.30%, at

8. Viscosity (7% solution in methyl isobutyl ketone at 26 C., Ford cup,#4 orifice) not less than 14 seconds.

9. Vinyl chloride content 84.5% to 92%.

This resin in the form of fine powder was dispersed in acetone having awater content of 0.4% to form a dope containing 23% by weight of resin.The dispersion of resin in the solvent was effected at 50 C. by means ofa heated doughtype mixer provided with means for slow solvent reflux. At25 C., the viscosity of the resin dispersion was not measurable byordinary means. At 50 0., its viscosity was determined as 200,000centipoises. This dispersion was] filtered in a plate-and-frame filterpress, usinga filter pad consisting of-several layers of cheesecloth and4 oz. cotton batting, followed by several thicknesses of specialfiltering cloth. An operating pressure of between 250 and 350 pounds persquare inch was sufiicient to force the dope through this filter. Thematerial was moved and handled by means of high-pressure gear-typepumps. All of the storage tanks and conduits were jacketed to permitthem to be maintained at a temperature of about 50 C. by means of hotwater. The filtered dope was de-aerated by allowing it to stand for 48hours at about 50 C.

The filament extrusion operation was carried for use.

out in a device very similar to those commonly used for thedry-spinning" of other materials. The resin dispersion was fed to thespinning machine by means of metering pumps which discharged to acandle-filter located near the top and within the drying cell proper.Immediately adjacent to the candle-filter was the spinnerette, which was1.5 inches in diameter, provided with 40 orifices, each having adiameter of 0.06 mm. The drying cell itself was a water-jacketedvertical cylinder 8 inches in inside diameter, provided with a bobbintake-up at its lower end. The effective filament drying space in thiscell was about 16 feet in length. The temperature of the water in thedrying cell jacket was maintained at C., and heated air, also at 80 C.,was admitted to the drying cell at the rate of 5 cubic feet per minute.The air was admitted near the top of the cell at the spinnerette faceand directed by means of a cone bailie transverse to the travel of theextruded filaments. The drying air, laden with solvent vapor, waswithdrawn from the lower part of the cell by means of a suction pump.The filaments at the bottom of the cell were gathered together through aguide and then wound parallel on a bobbin, the thread crossings and cakebuild being controlled by the usual equipment. The rate of filamentpassage through the drying cell was 250 meters per minute, and thefilament denier was between 2.5 and 3.0.

After the filaments had been allowed to stand for at least 12 hours onthe take-up bobbin, the yarn was twisted by means of a. standard duplexring twister. The amount of twist imparted was six turns per inch in theyarn. The thread in this operation was delivered to the twisting devicefrom the spinning bobbins immersed in a water bath. As pointed outbefore, the water picked up by the thread from this bath served both tolubricate the thread and to eliminate static electrical charges.

The twisted yarn was next stretched by immersing the spool on which itwas contained in water containing a small amount of the sodium salt ofthe sulfate ester of a 17 carbon atom branched chain secondary alcohol,which served as a wetting agent. The thread was then guided to apositively driven roll around which it was wrapped a few times topreclude slippage. From this roll the thread was passed upward to atakeup spool, also positively driven, at a sufficiently higher speed toimpart a stretch of to the thread. After this operation, the stretch wasset in the yarn by immersing it for about 2 hours, while on the take-upspool, in a bath of water heated to about 65 C. Following thistreatment, the yarn was given a second stage stretching in the samemanner as before, and the extent of stretch was 20% of its length. Thetotal stretch imparted by these two stretching operations thus amountedto about based on the original yarn. The stretching operations werecarried out with a thread travel of meters per minute. In the stretchingoperation, the amount of twist in the yarn and its denier were reduced.

For a. period immediately following the final stretching operation theextended yarn shows a marked tendency toward contraction. Thischaracteristic was controlled as indicated by immersing the spoolscontaining the stretched yarn in water heated to 65 C. for a period of 2to 3 hours. The final yarn was then coned ready It possessed a wettenacity of 2.75

grams per denier, with an elongation of 15%.

s m m m u m 5 &3 Wm we mi mw mmwmmmmmm m m m m mm M 37M mmmm wemw mwmwmm mm mm m mmwum m mm mmm m m m m mm mmmwwm mscmmmhmmmmmm a w m.mmmmmm.a%mmmm m mm m mmmmmmmmmxmemia 3 s an E a. w mm mmwwmwmm w WW M MWMM m mmm Ne s M m.mm fi. n wsm mm am mmm mwmmafi mmme N a a M m m W m a w ra hm m m m u mmmwmmmwrmwmmm wwwamm The may be dyed by incorporating dye- Mn th take-up stufls in the resin dispersion prior to filament W Wextrusion, or it may be dyed, after its formation, a ,1; 65' c, f pu'lodfrom baths containing mixtures of solvents and and "ed m at non-solventsfor the resin which temporarily themmflngmd swelitheyarn.Itcanalsobedyedbymeansof shown in the preceding W of dye-stuiis accordino s and rd on m; m m given dyeing procedures which are modified slightlyas 40 turns per mob from bobbins imto temperature and the us f disprsine a ents ma th a..- m. for the dye. Some oil-soluble dyes can beapplied to the yarn from hydrocarbon baths. pools 0|"III:Asistheusuaipracticewithtextilefiberait m a mm m m istrequentlydesirable todeluster or dull the fed to the stretching device. The yarnM T1118 m be complished by incorpora z Mmwdrlvenronpigmentssuchastitaniumdioxideofsmallparin a m mm heated t 90- c ticiesize in the resin dispersion, and the degree The m m mm to the m betmnoi delusterization can be controlled by variation of the particle sizeof the pigment and the 0 Med 5 The m amount used. It is preferable toachieve the deot the yarn in the stretching operation agm The M m theninvolve the incorporation of other substances in the filaments. As shownabove, this may be eftectively done by treatment of the filaments with uheated water at their point of formation, coupled with the additionaldelustering eflected by m the softness, elasticity and tensile strengthof the m uniform the 801m and yarn. The application of water heatedabove 50' C. to the filaments as they leave the spinning cell causes thefibers, when viewed under the microscope, to have a slightly roughenedor scaly exterior. This surface modification of the fibers 05 is highlydesirable, and is a further instance of the manner in which theproperties of the new fibers of this invention resemble those of naturalfibers.

This yarn lends itself readily to all ordinary 70 The yarn in theforegoing examples textile processing, and it can be knitted, woven,braided and plaited readily. It is especially wellfllemierlotthisinvmflomcneoi'themostadaptedtoknittingoperationaandtestshave ori'whichisthehightrueelasticityshownthatitispossibletoobtainamuchtightottheyarn.'lhepracticalvalueotthenewfiben 'erstltch without threadrupturethanisthe case 1 WWW thattheyarnwassetintheyarnbylmmersingthespoolscontainuingitinwaterheatedtoBfa'CJoraperiodot about 3 hours. Theresultingyarnhad a wet handotthestretchedyarmitwassubjectedtoamoperationinwhichtheyarniromthe stretchertake-upspoolswasathighspeed 5aroundaaeriesotsmallrollersoperatingimderwaterandarrangedtocuisetheyarntochangedirecflmthroughasharpangleninetimeaaiter whichitpassedtotake-upbobbins.Following thisopentimtheyarnwasconedandpackaged toruse.

posaeesedthetypicaipmpm'tiesotthenewtexmentl-waaprecluded. Thebobbinswaathenm'eparedfor of hours.

thisrollandasecondrolldrivenatahigherspeed with previously known yarns.In weaving it may be used either as filling, warp or pile. It isdesirable to carry out weaving operations with this yarn'underconditions of high relative humidity in order to reduce the developmentof static electrical charges. Due to the unusual resistance of the yarnto water, it can be' woven while wet without sacrificing strength orrisking thread breakage or undue stretching. In weaving, hygroscopicwarp sizing should be used which will form a pliable film on the thread.

If the yarn after being stretched is not subjected to a. stretch-settingtreatment, it shows a tendency toward shrinkage which is variable indegree according to the temperature to which it is subjected. Ingeneral, this tendency towards shrinkage in the unset yarn variesaccording to the table below:

Tempera- Shrinkage, ture, C, percent Where this contraction amounts toas much as 10%, a reduction in luster accompanies it. Shrinkage of theyarn also results in reduction in tenacity and an increase in elongationproportional to the extent of the stretch which is lost. After the yarnhas shrunk as a result of being subjected to elevated temperatures, itno longer shows any tendency toward contraction when reheated to thesame or a lower temperature. This shrinkage of the unset stretched yarncan be utilized in manyapplications of the yarn to tighten the stitch inknitted or woven materials and thereby to prevent "laddering or threadslippage.

The yarn can be produced in many filament sizes, and it has beendetermined that the filament denier which most conveniently lends itselfto the processes of textile manufacture is aroun 1.0 to 1.5.

The unusual propertiesof the new yarn make possible many applicationswhich take advantage of its remarkable true elasticity, waterresistanceand high wet strength, together with its resistance to attack bychemical influences or micro-organisms. For example, it is of value inindustrial filtering fabrics; in fishing lines, nets and seines; informing acidand alkali-resistant clothing; protective pipe coverings;electrical insulation; shower curtains; bathing suits; waterproofclothing; fire-proof awnings and curtains; hosiery; fusibleshape-retaining fabrics; and, in admixture with other textile materials,mixed fabrics for obtaining cross-dyeing eiiects and the like. The newyarn is useful in pile fabrics such as velvet, and it can beadvantageously employed as either the backing or the pile or both. Thestaple fibers of this invention, in admixture with natural materialssuch as cotton and wool, make possible the production of fabrics whichwill retain a pressed fold, and improve mercerlzing and l. Textile fibercomposed of a vinyl resin substantially identical with a resin resultingfrom the conjoint polymerization of a vinyl halide with a vinyl ester ofan aliphatic acid, which contains from about 80% to 95% by weight of thehalide in the polymer and which has an average macromolecular weight ofat least 15,000.

2. Textile fiber composed of a vinyl resin substantially identical witha resin resulting from the conjoint polymerization of a vinyl halidewith a vinyl ester of an aliphatic acid, which has an averagemacromolecular weight of at least 15,000 and which is substantially freefrom lower molecular weight polymers.

3. Textile fiber composed of a vinyl resin substantially identical witha resin resulting from the conjoint polymerization of a vinyl halidewith a vinyl ester of an aliphatic acid, which has an averagemacromolecular weight of at least 15,000 and which is substantially freefrom lower molecular weight polymers, said resin being completelydispersible in warm dry acetone and having a heat distortion point above65 C.

4. Textile fiber composed of a vinyl resin substantially identical witha resin resultingfrom the conjoint polymerization of vinyl chloride withvinyl acetate, which contains from about to by weight of the chloride inthe polymer and which has an average macromolecular weight of at least15,000, said resin having a heat distortion point above 65 C. and beingcompletely dispersible in acetone containing less than 0 0% by weight ofwater at about 50 C.

5. A textile fiber formed of a vinyl resin substantially identical witha resin resulting from the conjoint polymerization of a vinyl halidewith a vinyl ester of an aliphatic acid, which contains from about 85%to about 90% by weight of the halide in the polymer and which has anaverage macromolecular weight of at least 15,000,

said fiber being characterized by resistance to deterioration instrength on exposure to ultraviolet light, and by water-resistance,non-inflammability, immunity to attack by bacteria and fungi, andresistance to alkalies and mineral acids,

6. Staple textile fiber formed of a vinyl resin substantially identicalwith a resin resulting from the conjoint polymerization of a vinylhalide with a vinyl ester of an aliphatic acid, which contains fromabout 85% to about 90% by weight of the halide in the polymer and whichhas an average macromolecular weight of at least 15,000, said fiberbeing characterized by resistance to deterioration in strength onexposure to ultra-violet light, and by water-resistance,thermoplasticity, non-infiammability, immunity to attack by bacteria andfungi, and resistance to alkalies and mineral acids.

7. A textile fiber formed of a vinyl resin substantially identical witha resin resulting from the conjoint polymerization of a vinyl halidewith a vinyl ester of an aliphatic acid, which contains from about 85%to about 90% by weight of the halide in the polymer and which has anaverage macromolecular weight of at least 15,000, said fiber beingcharacterized by true elasticity, high strength, resistance todeterioration in strength on exposure to ultra-violet light, and bywaterresistance, non-infiammability, immunity to attack by bacteriaandfungi, and resistance to alkalies and mineral acids.

8. Synthetic textile yarn formed of filaments composed of a vinyl resinsubstantially identical with a resin resulting from the conjointpolymerall-elongation of from 10% to 35%.

0.8ynthetictextileyarniormedoifiiaments eunposed ct a'vinylresinidentical 10witharesinresultingtruntheconjdntpolymerimtkmoiavlnyihalidewithavinylesterofanaliphatic acid, which contains fromabcut 80%to%byweightofthehalideinthepolymerandwhichhasanaveragemacrcmolecularweightoi iiatleastl5,000,saidyarnhavingatenadty oiatleast2.0gramsperdenierandanelongationof from to% andwhichhasbeeninitially stretchedtotheextentoibetween'l5%and200%.

4o cous and slowly fiowable at a temperature of 12. Knitted fabrics orarticles comprising yarn 'iormedotfilamentsotavinylrminmbstantiallyidentical with a resin resulting from the conjoint polymer-ladenoiavinylhalidewithavinylester of an aliphatic acid, which contains fromabout 00%to05% byweightoi thehaiideinthepo ymet and which has an averagemacromolecular weight of at least 15,000, saidyarn having beenstretchedbetween'fi'ltandmit.

18. Woven iabrlcs or articles comprising yarniormedoifilammtsotavinylresin identical with a resin resulting from theconjoint polymerization of a vinyl halide with a vinyl ester of analiphatic acid, which contains from about80%to9fi%byweightoithehalideinthe polymer and which has an averagemacromolecularweightofatleastl5,000,saidyarnhaving been stretched betwemand 200%.

14. Pile fabrics or articles in which the pile isoiyarniormedotfilamentsoi avinyl resin substantially identical with aresin resulting from the conjoint polymerization 01 a vinyl halide witha vinyl ester 0! an aliphatic acid, which containsiromabout% to%byweightoithe halideinthepolymerandwhichhasanaverage macromolecularweight of at least 15,000, said yaan having been stretched between 75%and l5. Braided articles, lines and cords comprising yarn formed offilaments of a vinyl resin substantially identical with a resinresulting from the conjoint H H ofavinylhalidewitha vinyl ester of analiphatic acid, which contains from about 50% to 95% by weight of thehalide in the polymer and which has an average macromolecular weight 01'at least 15,000, said yarn having been stretched between 75% and 200%.

16. Synthetic textile fibers, fabrics and articles comprising yarncomposed of filaments formed of a vinyl resin substantially identicalwith a resin resulting from the conjoint polymerization of a vinylhalide with a vinyl ester of an aliphatic acid, said resin containingfrom about 80% to about 95% by weight 01' the vinyl halide in thepolymer and having an average macromolecular weight of at least 15,000,said yarn having been stretched to the extent of from 75% to 200% andbeing characteried by high tensile strength in the wet state, hig trueelasticity, controllable shrinkage, w 1 to water, alkalies and mineralacids, to attack by bacteria and fungi, non-bill crease resistance,thermoplasticity, electrical insulating qualities, controllable luster,and high flexibility.

EDWARD w. RUGELEY. THEOPHILUS A. mm), JR. JOHN F. cormon.

D ISCLAI MER 2,161,766.Ed1m'rd W. Bugclcy, flcophilus A. Fel'ld, Jr.,and John F. Co'nlo'n, Charleston, W. Va.

hon

Sm-nnmc Fmnn. filed July 22, 1946, by the ac,

Patent dated June 6, 1939. Disclaimer Gdrb'ide and Carbon ChemicalsCorpora- Hereby enters this to claims 1 to 6 inclusive, and claim 11 inthe said specification.

lofici l Gazette A 20, 1946.]

